Before seeding, the seed bed is prepared by thatching, harrowing, ploughing or tilling the soil. It has been shown that tamping of the soil surface which has been loosened up by the ground preparation equipment is desirable, in order to ensure suitable compactness of the seed bed. Proper compacting of the soil creates sufficient capillary attraction so that the upper soil layer will not dry out and thus impair the germination of the seeds. If the soil is too loose or porous, on the other hand, there is a risk of the seeds landing in cavities and being too deeply imbedded in the ground, which will impede their development into seedlings.
In agriculture and nursery operations, it is known to flatten or tamp the soil by means of a roller before sowing the seeds. In forestry, this method is not suitable, because of the greatly varying and sometimes very difficult terrain conditions. The presence of tree branches and tree stumps, and, particularly, large stones and hollows in the ground, renders the use of wheel devices impractical.